We're not automatons. We are responsible for our actions. But our baked-in biases can make us susceptible to infidelity. Our brains can be a battlefield of competing interests, and sometimes desire wins. It may win more often in people like Petraeus whose bold, creative thinking we so admire can come with a bias toward behavior we don't. This doesn't make him special, it makes him human.
Brian Alexander is a journalist and author whose books include "Rapture: How Biotech Became the New Religion" and "America Unzipped: The Search for Sex and Satisfaction." He and Larry Young are co-authors of "The Chemistry Between Us: Love, Sex, and the Science of Attraction."